This invention relates to valves and in particular to a specially constructed valve suitable for withdrawal of vapor or liquid from a pressurized container.
In withdrawing fluids from a pressurized vessel containing both vapor and liquid under pressure, it is sometimes desirable to withdraw vapor and at other times to withdraw liquid only. There are several valves or similar devices which, when mounted on or attached to the top of such pressure vessels permit the withdrawal of vapor or liquid selectively. Typical valves of this kind are described, for example, in U.S. Pat. Nos. 2,365,423 and 3,021,870. However, these valves as well as many others which are currently in use are often complicated to construct and expensive to fabricate.
In the shipment of refrigerants in recent years it has become increasingly necessary and commercially desirable to ship the refrigerant (usually fluorocarbons) in low-cost, pressurized cylinders without a conventional discharge valve. Simplicity of construction and economy of fabrication of such cylinders have become of paramount commercial importance and have in turn resulted in the use of so-called "disposable" cylinders which can be discarded after use by the consumer. Simplicity in cylinder construction has in turn necessitated simplicity and economy of the types of dispensing mechanisms and devices which must be employed with such cylinders.
Accordingly, this invention provides a valve device which can be readily attached on a pressurized vessel containing both vapor and liquid under pressure and which can be conveniently operated to withdraw vapor or liquid selectively. The valve described herein is simple and inexpensive to construct and is therefore readily adaptable for use with such disposable cylinders, although it is equally adaptable for reusable cylinders.